Determination of degradation constant of Li ion from 10B(n,αγ)7Li reaction in various media

Abstract

Abstract A Li ion from a 10B(n,αγ) 7Li reaction induced by a thermal neutron undergoes a large degradation due to its high stopping power in a medium. This phenomenon influences the peak line shape of the 477.6 keV gamma line emitted from an excited 7Li nucleus recoiled by an energetic alpha particle and the peak line shape in a spectrum varies according to the slowing-down media. A numerical study for the analysis of the line shape has been conducted by performing a parametric search and fitting the measured spectrum in a least squares approach by Choi et al. and implemented in a recent version of HYPERGAM code. In this study, the gamma-ray spectra were measured for various media like elemental boron, boric acid, borax, boron carbide, boron steel and so on at a SNU-KAERI prompt gamma activation analysis facility of the HANARO research reactor in Korea Atomic Energy Research Institute. The degradation constant was determined for various slowing-down media.